Unlu Bekir Asilcan, Kirit Esen, Celik Dogantan, Yildiz Elif Akhuseyin, Karatay Ahmet, Boyacioglu Bahadir, Ünver Hüseyin, Yilmazer Açelya, Yıldız Mustafa, Elmali Ayhan
Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Beşevler, Ankara, Türkiye.
Graduate School of Natural and Applied Sciences, Ankara University, 06100 Ankara, Türkiye.
ACS Appl Bio Mater. 2025 Jul 21;8(7):6261-6277. doi: 10.1021/acsabm.5c00750. Epub 2025 Jul 1.
Tris (2-aminoethyl)amine (TREN) functionalized N-doped graphene quantum dots (N-GQDs) and their Ag, Pd, and Pt nanocomposites were synthesized via a green one-step method and comprehensively characterized using FT-IR, UV-vis, TEM, and EDX. Spectroscopic analysis revealed π-π* transitions of C═C bonds (245-250 nm) and -π* transitions of C═O and C═N bonds (334-350 nm), elucidating the materials' optical properties. Photoluminescence studies revealed excitation wavelength-dependent emissions, indicating the presence of edge defect levels. Femtosecond transient absorption spectroscopy revealed a shortened excited-state lifetime upon incorporation of a metal atom into TREN-GQDs. Nonlinear absorption was explored by using the open-aperture Z-scan method, revealing enhanced performance upon incorporation of plasmonic nanoparticles. Ag-incorporated samples exhibited the highest NLA response due to plasmon-enhanced two-photon absorption. Notably, Pt-incorporated N-GQDs showed improved NLA and good biocompatibility with the intracellular fluorescence response, positioning them as promising candidates for bioimaging applications. Density functional theory (DFT) calculations, including gas-phase optimizations and aqueous simulations, confirmed alignment with experimental results, highlighting the enhanced stability and reactivity of nanocomposites. These findings highlight the potential of these materials in various applications, such as optical limiting, imaging, photovoltaics, and sensing applications.
通过绿色一步法合成了三（2-氨基乙基）胺（TREN）功能化的氮掺杂石墨烯量子点（N-GQDs）及其银、钯和铂纳米复合材料，并使用傅里叶变换红外光谱（FT-IR）、紫外可见光谱（UV-vis）、透射电子显微镜（TEM）和能谱仪（EDX）对其进行了全面表征。光谱分析揭示了C═C键的π-π跃迁（245 - 250 nm）以及C═O和C═N键的-π跃迁（334 - 350 nm），阐明了材料的光学性质。光致发光研究揭示了与激发波长相关的发射，表明存在边缘缺陷能级。飞秒瞬态吸收光谱表明，将金属原子掺入TREN-GQDs后，激发态寿命缩短。通过开孔Z扫描法研究了非线性吸收，结果表明掺入等离子体纳米颗粒后性能增强。由于等离子体增强的双光子吸收，掺入银的样品表现出最高的非线性吸收响应。值得注意的是，掺入铂的N-GQDs显示出改善的非线性吸收以及与细胞内荧光响应良好的生物相容性，使其成为生物成像应用的有前途的候选材料。密度泛函理论（DFT）计算，包括气相优化和水相模拟，证实与实验结果一致，突出了纳米复合材料增强的稳定性和反应性。这些发现突出了这些材料在各种应用中的潜力，如光学限幅、成像、光伏和传感应用。
